tmakin/ack-tegra
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mm, slab: clean up slab->obj_exts always

Browse Source 
commit be8250786ca94952a19ce87f98ad9906448bc9ef upstream.

When memory allocation profiling is disabled at runtime or due to an
error, shutdown_mem_profiling() is called: slab->obj_exts which
previously allocated remains.
It won't be cleared by unaccount_slab() because of
mem_alloc_profiling_enabled() not true. It's incorrect, slab->obj_exts
should always be cleaned up in unaccount_slab() to avoid following error:

[...]BUG: Bad page state in process...
..
[...]page dumped because: page still charged to cgroup

[andriy.shevchenko@linux.intel.com: fold need_slab_obj_ext() into its only user]
Fixes: 21c690a349 ("mm: introduce slabobj_ext to support slab object extensions")
Cc: stable@vger.kernel.org
Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Harry Yoo <harry.yoo@oracle.com>
Tested-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Link: https://patch.msgid.link/20250421075232.2165527-1-quic_zhenhuah@quicinc.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
[surenb: fixed trivial merge conflict in alloc_tagging_slab_alloc_hook(),
skipped inlining free_slab_obj_exts() as it's already inline in 6.12]
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Zhenhua Huang
2025-04-21 15:52:32 +08:00
committed by Greg Kroah-Hartman
parent e10ec6e32b
commit dab2a13059
1 changed files with 7 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

27
mm/slub.c
View File

@@ -2035,18 +2035,6 @@ static inline void free_slab_obj_exts(struct slab *slab)
slab->obj_exts = 0;
}
static inline bool need_slab_obj_ext(void)
{
if (mem_alloc_profiling_enabled())
return true;
/*
* CONFIG_MEMCG creates vector of obj_cgroup objects conditionally
* inside memcg_slab_post_alloc_hook. No other users for now.
*/
return false;
}
#else /* CONFIG_SLAB_OBJ_EXT */
static inline void init_slab_obj_exts(struct slab *slab)
@@ -2063,11 +2051,6 @@ static inline void free_slab_obj_exts(struct slab *slab)
{
}
static inline bool need_slab_obj_ext(void)
{
return false;
}
#endif /* CONFIG_SLAB_OBJ_EXT */
#ifdef CONFIG_MEM_ALLOC_PROFILING
@@ -2099,7 +2082,7 @@ prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p)
static inline void
alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags)
{
if (need_slab_obj_ext()) {
if (mem_alloc_profiling_enabled()) {
struct slabobj_ext *obj_exts;
obj_exts = prepare_slab_obj_exts_hook(s, flags, object);
@@ -2577,8 +2560,12 @@ static __always_inline void account_slab(struct slab *slab, int order,
static __always_inline void unaccount_slab(struct slab *slab, int order,
struct kmem_cache *s)
{
if (memcg_kmem_online() || need_slab_obj_ext())
free_slab_obj_exts(slab);
/*
* The slab object extensions should now be freed regardless of
* whether mem_alloc_profiling_enabled() or not because profiling
* might have been disabled after slab->obj_exts got allocated.
*/
free_slab_obj_exts(slab);
mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s),
-(PAGE_SIZE << order));